Lenticular print image display device is specially prepared graphics that are designed to work with a lenticular lens that allows the viewer to see different images depending on the angle at which it is viewed.
To impart a three dimensional effect, images are printed in an interlaced format. A lens sheet is place on top of the image that serves as a decoder for the image that is printed behind it. The lens sheet is a transparent plastic sheet that contains one side with lenticular lenses with a specific height, which have been extruded, cast, or embossed with an array of identical parallel lenses or a plurality of semispherical convex lenses arranged in a specific pattern. Conventional extrusion process generally provides a lens material thickness of about 10 mils (250 microns) to 40 mils (1000 microns) due to the extrusion process limitation. Also thicker lens materials minimize film distortion in lenticular print image devices. The other side of the lens sheet remains smooth. Images can be printed directly on this smooth side of the lens sheet (known as Direct-to-lens Process) or can be affixed onto the aforementioned side of the lens sheet.
Precise alignment of the image and lens sheet is paramount to achieve the desired three dimensional effects in a lenticular print. The image itself is a composite of two or more graphics that are interlaced together. Each individual lenticular lens must be perfectly aligned with the interlaced image underneath it in order for the effect to work. Based on the angle of the viewer, each lenticular lens acts as a magnifying glass to enlarge and display the portion of the image below. The lenticular lens receives light that passes from the direction of the flat surface toward the ridges and directs such light in a way that sends different portions of the light entering each lenticular lens to different portions of a viewing area in front of the lenticular lens. Plurality of lenticular lenses work in harmony to form the entire lenticular image. Thus, lenticular print can appear to show motion or even give off three-dimensional effect because each eye is viewing the lenticular print from its own angle.
The lenticular print image display device requires a transparent plastic lens sheet with a specific height. The lenticular lenses are formed atop of the transparent plastic lens to form the device.
In U.S. Pat. No. 7,514,140 to Tsukuda, issued Apr. 7, 2009, entitled “Acrylic Film for Lens Substrate, Lens Film Using the Same Lens Sheet,” describes a lens substrate which requires an acrylic film. The film has a specific thickness, and a lens layer is created on top of the film to suppress any warping or sagging deformations.
In U.S. Pat. No. 7,639,426, issued Dec. 29, 2009, entitled “Micro-lens Enhanced Element,” describes methods and apparatuses forming micro-lens enhanced images. The micro-lens apparatus also require a transparent layer with a specific thickness that separates an image from lenticular lens.
U.S. Pat. No. 6,628,460, issued Sep. 30, 2003, entitled “Lens Sheet and Method for Producing the Same,” provides a lens sheet comprising a transparent substrate and a lens portion, with a relaxation layer between the transparent substrate and the lens portion. It is disclosed that the relaxation layer is 1-30% of the height of the lens unit.
US Pat. Publication No. 2006/0285215, published Dec. 21, 2006, entitled “Printing Method for Making a Lenticular Lens Material,” provides a direct-to lens method for creating a lens material using energy curable inks and coatings. An image is printed on the back sheet of a transparent substrate sheet and the energy-curable ink is printed on the back sheet of the transparent substrate.
The above described lenticular print three dimensional image display lenses require a transparent sheet transposed between the lenticular lenses and the image with a specific thickness of the transparent sheet. The use of such technique typically requires the display to be co-extensive with the entire area of the image. However, cost, weight and other factors often cause a publisher to wish to avoid publishing entire pages of documents in lenticular form. Thus, for example, it may be useful to provide a three-dimensional image as a part of a sheet or page of a book, it is much less desirable to do so where such an image will occupy an entire page. Also, precision alignment and tight registration of the interlaced images with the lenticular lenses makes forming the lenticular device difficult. Corrections of the distortion of the lens due to misalignment require special printing techniques, custom equipment and set-up.
Thus, there remains a need for a simple, flexible and efficient method to create useful lenticular lens type three dimensional image displays. There is a further need for arrangement of lenticular lens that can be used with co-designed printed images to provide enhanced articles that provide particular visual effects and that can be formed in a reliable fashion using generally available commercial resources. The current invention fulfills this need.